Research on specialized nanoparticle coatings are leading to novel applications for example in photonics, catalysis, sensors, and biomaterials. The assembly of nanoparticles into conformal and uniform thin films with precise control over chemical and physical properties poses a significant challenge and requires advanced tools. KSV NIMA offers a range of solutions for creating precise nanoparticle coatings.
Langmuir-Blodgett and Langmuir-Schaefer technologies are used to deposit oriented insoluble molecular layers on a solid substrate. These technologies are also suitable for depositing various nanoparticle layers, such as nanowire, nanorod layers, and graphene films. End-applications for the coatings vary from biochemical sensor array formation to creating anti-microbial and -reflective coatings, electro-optical devices and environmentally responsive coatings.
Langmuir-Blodgett and Langmuir-Schaefer depositions are effective methods for the manufacture of single-molecule layers. Alternate dipping expands this further, allowing simultaneous deposition of two different components and also gives control over molecular orientation in the forming layer.
Main benefits of the LB and LS technology for nanoparticle coatings
- Precise control of the monolayer (thin film) thickness and packing density
- Homogeneous deposition over large areas
- Enables multilayer structures with varying layer composition
- Deposition can be made on any kind of solid substrate
Anti-microbial coating is an example of a smart coating that uses silver nanoparticles. Silver nanoparticles are known for their anti-microbial properties and can be incorporated in many types of surface layers and coatings.
Performing the coating is increasingly facilitated by using a Brewster Angle Microscope to monitor the homogeneity of the nanoparticle layer prior to coating. This will save time and money by not having to coat low-quality layers that are detected only after deposition. KSV NIMA Thin Film Deposition Solution package has been formed to include all the necessary tools for effective nanoparticle deposition.
Dip coating can be applied to a large variety of materials from the inorganic sols and inorganic nanoparticles to self-assembling biochemical systems. Applications include deposition electrical- and electro-optical layers, anti-reflective coatings, creating super hydrophobic surfaces and depositing biologically compatible coatings. Dipping speed, temperature and drying times have a great effect on layer properties. Multi-vessel dipping can be used to fabricate complex self-assembled systems with large sequences with improved reproducibility.
Dip coating of inorganic sols (or sol-gel synthesis) is also a way of creating nanoscale inorganic or polymeric coatings. In sol-gel synthesis, the deposition speed is a highly important parameter that affects, for example, layer thickness, density and porosity.
For more information, see:
- Application Note 3 — Deposition and Characterization of Single-Sheet Graphene and Graphene Oxide Films
- Application Note 10 – Nanostrand Formation of Block Copolymers at the Air/Water Interface
How to create a highly controlled nanoparticle coating with KSV NIMA Deposition Solution package in practice?
- Choose the nanoparticle and substrate to be used. Substrate can be any material and any floating nanomaterials can be used, but they should be similar in chemical nature for good adhesion between the particles and the substrate.
- A cleaned KSV NIMA LB Trough is filled with water or saline solution, such as CaCl2. This will stabilize the particles for deposition.
- The particles are introduced at the air-water interface by using e.g. a syringe or a syringe pump.
- Barriers will start compressing the particles closer to each other. While doing so, KSV NIMA MicroBAM is visualizing the nanoparticle layer to determine its homogeneity. With an unknown material, an isotherm will be formed by compressing the particles until the layer will collapse. From this isotherm, the optimal packing density for deposition will be determined. When the deposition packing density has been decided, the KSV NIMA LB Trough compresses to this density and holds it.
- The solid substrate is fixed to the dipper which will perform the coating. MicroBAM image will indicate the layer homogeneity. When layer is homogeneous, the dipper will create the coating using preset parameters either vertically (LB) or horizontally (LS) depending on which is the preferred method.
- After the coating is done, the substrate can be further characterized as required. The entire coating process for a familiar material may take less than an hour.